Air-break switch.



l. R. TOWNSEND.

AIR BREAK SWITCH.

APPLICATION FILED NOV. 26. I915.

1,275,326. Patented Aug. 13, 191%;

2 SHEETSSHEET 1.

J. R. TOWNSEND.

AIR BREAK SWITCH.

APPLICATION FILED NOV. 26. Hi5.

1,275,326. Patehted Aug.13, 191&

2 SHEETS-SHEET 2.

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Application flied November 26, 1815. Serial No. 88,688. v

To all whom it may concern:

Be it known that I, Jomv R. TowNsnNn, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and use ful Improvements in Air-Break Switches, of

i which the following is a specification.

My invention relates to air-break switches, and refers particularly toswitches which :are used for openin the circuits of hightenslontransmission mes.

The air-break switches of the class to which my invention belongs areordinarily mounted on the tops of poles or towers, which carry thetransmission lines. In the. usual -3-phase system three conductors leadto an air-break switch and three conductors lead from this switch, theswitch itself having three sets of contacts which serve 'to bridge therespective conductors and make electrical connection therebetween. Asthe current transmitted over a high-tension system is often in excess of60,000 volts, it will be apparent that unusual precautions must be takenin connection with the construction of air-break switches to preventdestructive and dangerous arcing when the switch is opened, therebyinterrupting the circuit.

It is the ob ect of my invention to open a high-tension circuit quicklyand surely without the formation of a destructive arc and without dangerof enabling the current to strike from one of the parallel conductors orphases to another, thus causing shortcircuiting of the system.

It is a further object of my invention to provide auxiliary contacts,which remain in engagement with each other after the main contacts havebeen separated from each other, so that all of the arcing will takeplace at the auxiliary contacts, which are of relatively cheap material,and which, owing to the construction of my improved switch, are quicklyseparated from each'other by a wide gap on opening of the switch,thereby causing the rapid and certain breaking of the are.

A still further object of my invention resides in constructing the twooperating halves of the switch so that the parts rotate in a verticalplane and in opposite directions at the same rate of speed, mechanismalso being provided so that abrupt and sudden movement'of the switch ator near its closed and full open positions is avoided, thus doing awaywith danger of injuring the Specification of Letter! we. Pate ted 13,1918.

switch on account of careless handling under the. stress of excitementor for other cause.

A still further object of my invention resides in the provision of aprotector for the that the operation of the main contacts so latter maynot be interfered with by accumulations of sleet or ice on the contacts.The protector is so constructed that it serves to cover the contactswhen theilatter are both in closed and open positions.

A still further ob]ect of my invention resides in the means forconnecting the switch with the conductors which it serves to bridge sothat there is no possibility of any loose or flexible conductor comingin contact with a grounded framework or other insulated parts, whichmight cause injury to life or property.

These and other advantages of my invention will be more readilyunderstood by reference to the accompanying drawings, in which- Figure 1is an end elevation of my improved switch, showing its operatingmechanism connected therewith;

Fig. 2 is a plan of the switch shownv in Fig. 1;

Fig. 3 is a fragmentary sectional view taken on the line 33 of Fig. 2,and showin the drag link used to connect the two si es of the switch;

Fig. 4 is a vertical section throu h one of the cross-pieces, showingone of t e toggle guides attached thereto;

Fig. 5 is an enlarged section through the auxiliary contacts, showing aplan of the contact guide; and

Fig. 6 is an enlarged plan of the main contacts and sleet protector, aportion of the latter being broken away.

In Fig. 2 I have shown my improved switch as constructed for a 3-wiresystem, the conductors 10 leading to the insulators 11, which, in turn,are anchored to the stringers 12. Although I have shown three pairs ofconductors, it will be evident that braced by means of the cross-braces15. Resting on the stringers 12 are the channel irons 16, which areprovided at their ends with the bearings 17, which serve to support thetwo shafts 18. These shafts extend the entire len th of the stringers12.

On each of the shafts 18 is mounted the insulator support 19 carrying apetticoat 1nsulator 20. Each of the insulators 20 carries at its outerend the bracket 21, which, in turn, carries the contact rod 22, ofcopper, brass, or other suitable conductmg material. As most clearlyshown in Fig. 6,one of the contact rods 22 has attached thereto thecontact blade 23, whereas the opposite contact rod 22 carries the springcontacts 24, 24, between which the contact blade 23 is adapted to beinserted and form snug contact therewith. By using the form of contactswhich 'I have just mentioned severe jar is avoided when the contactblade 23 is brought into connection with the spring contacts24.

Each of the contact rods 22 has a flexible steel auxiliary contact 25attached thereto, one of these auxiliary contacts carrying near itsupper end the guiding V 26, by means of which electrical connectionbetween the two auxiliary contacts 25, 25 is insured when the switch isin closed position.

A link 27 is pivotally connected to the outer end of each of the contactrods 22, and is, in turn, connected at its outer end with a link 28which has its opposite end ivotally attached to the bracket 29 carriedby the conductor 10.

As clearly shown in Figs. 1 and 6, the contact blade 23 and the springcontacts 24 are protected, respectively, by the housing 30 closed at itstop and sides. When the switch is in closed position, as indicated infull lines in Fig. 1, the two housings 30 are brought into contact witheach other and form a tight joint on their inner ends so that the maincontacts, consisting of the blades 23 and the spring contacts 24, areeffectually protected from the action of snow, sleet, rain, or the like.In order to carry off water the housings 30 on their tops preferablyslope slightly from their inner to their outer edges. Each of thehousings 30 is pivotally connected to the corresponding contact rod 22by engagement of the screws 31 with the cross-member 32 carried by theend of the contact rod 22. A link 33 serves to connect each of thehousings 30 with a bracket 34, which is pivotally mounted on the link27.

In order to provide electrical connection between each air of conductors10 in the same line, eac of the links 28 is connected with thecorresponding conductor 10 through the flexible conductor 35, which, onone end, is suitably connected to the conthe conductor 37 connects thelink 27 with I the contact rod 22.

I will next pass to a description of the actuating mechanism for theswitch. This actuating mechanism is preferably located near one of theoles 14, as clearly shown in Figs. 1 and 2. The arms 38, rigidlymountedon the shafts 18, are'connected by the toggle 39, which consistsof the two rods 40 pivotally connected with each other at 41.

hese two rods 40 operate within the guides 42, which are suitablyattached to one of the channel irons 16, as clearly shown in Figs. 2 and4. A drag link 43 having the pivotally connected arms 44 mounted on theshafts 18 serves to insure that on rotation of one of the shafts 18 inone direction the other shaft will be rotated in the opposite directionat'the same rate of speed.

Pivotally' connected to the toggle 39 at the pivotal polnt 41 is thelink 45, which leads to the end of the arm 46 of the bell crank lever47, which is pivotally mounted at the point 48 on the prate 49, which iscarried by the pole 14. othe arm 50 of the bell crank lever 47 isattached the link 51, and to the arm 52 is attached the link 53. Thelowerends of the links 51 and 53 are attached to the respective ends ofthe lever 54 pivotally mounted at 55 on the plate 56 carried by the pole14. Each of the links 51 and 53 preferably has therein an insulatingsection '57 to act as a safeguard to prevent the passage of high-tensioncurrent to the o crating handle, which will next be.

descri ed. The operating handle 58 is attached to the lever 54, and whenthis operating handle is swung from the position in dicated in fulllines in Fig. 1 to the position indicated in dotted lines, the lever 54is rotated on its pivot 55 into the position shown in dotted lines. Thepole 14 carries a crossarm 59 so that when the operating handle 58 isswung from one osition to another a staple, or similar device, may beinserted through the aperture 60 in the handle 58 and passed into thecross-arm 59 so that the handle 58 will be held in the position to whichit has been moved.

Having thus described the various parts which are used in connectionwith my 'improved switch, the operation of the same may now be readilyunderstood:

When the switch is in closed position the various parts are as shown infull lines in Fig. 1'. The current passesfrom one of the main conductors10 through the flexible conductor 35, thence'throu h the link 28.flexible conductor 36, link 2 flexible conductor 37, and contact rod 22,through the contact blade 23 and spring contacts 24, to the oppositecontact rod 22, flexible conductor 37, link 27, flexible conductor 36,link 28, and flexible conductor 35, to'the main conductor 10 on the sideof the switch opposite to the conductor 10 first mentioned. It will thusbe evident that the circuit between the conductors 10 of the same lineis thus closed. When it is desired to open the switch, the handle 58 ismoved to the position shown in dotted lines in Fig. 1. Through theinstrumentalit of the lever 54 and the links 51 and 53, the bell cranklever 47 is moved into the position shown in dotted lines, so that thearm 46 is brought into engagement with the stop 61, the arm 52 havingbeen in engagement with the stop 62 when the bell crank lever was in theposition indicated in full lines. As the movement of the handle 58 andthe bell crank lever 47 begins to take place, the link 45 is movedupwardly, and causes the pivotal point 41 of the toggle 39 to be carriedupwardly until the link 45 and the arm 46 are brought into the sameaxis. This toggle 39 causes the arms 38 to be moved inwardly so that theshafts 18 are rotated in opposite directions. It will be evident that asthe pivotal point 41 of the toggle 39 first begins to move upwardly themovement communicated through the arms 38 to the shafts 18 will berelatively slow, but will become more rapid as the two rods 40 of thetoggle become disposed at a more acute angle to each other. On the otherhand, as the arm 46 of the bell crank lever 47 approaches its verticalposition, and thereby a dead center, the upper end of the link 45, and,therefore, the pivotal point 41, will travel upwardly at a slower rate(as sumin a uniform rate of movement of the operating handle 58), thisupward movement of the point 41 gradually decreasing in velocity untilthe link 45 and the arm 46 are brought into the same axis, whereu onfurther iotation of the shafts 18 stops. The gradual cessation ofmovement near the extreme open position of the switch, and a similaraction taking place when the switch is closed, is a feature of greatadvantage, inasmuch as it effectually prevents undue strains caused bysevere shoe s or jars which would otherwise take place if the switchwere carelessly or unskilfully operated. According to the constructionwhich I have just described, no matter how violently the operatinghandle 58 is moved from one extreme position to the other the switchitself is always opened or closed, as the case may be, without jar orshock.

As the shafts 18 are rotated in the manner just described, the movementof the two shafts is kept in synchronism b I the action of the drag link43. The insul ators 20 are moved outwardly into the dotted positions. Asthis movement takes place the contact blade 23 is withdrawn from thespring contacts 24 so that the passage of current through these maincontacts is interrupted. After the main contacts have been separated,however, the auxiliary spring contacts 25, which gradually straightenout as the insulators 20 are moved outwardly, are still maintained incontact with each other, so that the current passes from one contact rod22 to the other through these auxiliary contacts 25. The engagementbetween t e two auxiliarycontacts 25 continues until the point 41' ofthe to gle 39 has traveled approximately one-third ofits total distanceof travel .in a vertical plane. By this time the shafts 18 are rotatingat a considerable and gradually increasing rate of speed. The upper endsof the auxiliar contacts 25 are now uickly separate from each other, andt e parts are thereafter brought into the position shown in dottedlines. It will be evident that the arc-breaking distance between theends of the two auxiliary contacts 25 is very great in proportion to themovement of the switch as a whole, and an arc is thus quickly andeffectively broken not only on account of the great distance by whichthe auxiliary contacts are separated from each other, but also onaccount of the fact that when the separation takes place the movement ofthe auxiliary contacts in opposite directions is very rapid.

As the switch is moved from closed to open position, it will be evident.that the link 33 pivotally attached to the protector casing 30 and tothe link 27 willmaintain the protector 35 in position so that the lattercovers the contact blade 23, or the spring contacts 24, as the case maybe, when the 105 switch is in its full open position. In this way water,snow, sleet, and the like, are prevented from accumulating on the switchlade or spring contacts.

When it. is desired to close the switch the operating handle 58 is, ofcourse, moved from the position shown in dotted lines to that shown infull lines in Fig. 1. The auxiliary contacts 25 first engage each otherso that any arcing which results takes place at these auxiliarycontacts. The contact blade 23 is thereafter brought into en agementwith the spring contacts 24, and the normal passage of current, aspreviously described, takes place. The engagement of the contact blade23 with the spring contacts 24 is very efiicient, while at the same timethere is no violent shock or jar connected with this operation. Thisfeature, taken in con'unctionwith the gradual decrease inthe rapidity ofrotation of the shafts 18 as the full open and full closed positions ofthe switch are approached, greatly relieves the strain on the insulators20, and I have found by practical experience that the breakage of. 130

'or sense of my invention, as defined in the ap en ed claims.

hat I claim is: 1. In an electric switch, the combination of a pair ofmain contact members adapted said housings in rotecting position abovesaid engaging en s during rotation of said shafts in moving said switchfrom closed to open) osition.

5. u an electric switch, the combination of a pair of parallel shafts, acontact memto engage each other, means for separating said contactmembers from each other, a air of-anxiliary spring contact mmbers eac ofwhich is carried by one of said main contact members, said auxiliarycontact members adapted to engage each other during the engagement ofsaid main contact members and to be separated from each other only aftersaid main contact members have been separated from each other, and'aV-shaped guiding member carried by. one of said auxiliary contactmembers, whereby the engagement of the other auxiliary contact memberwith said first-mentioned auxiliary contact member is insured.

2. In an electric switch, the combination of a shaft, means for rotatinsaid shaft, an insulator carried by said s aft, a contact member carriedby said insulator, said contact member having an end adapted to engage acompanion contact member, a protector housing carried by and above theengaging end of said contact member, and means for maintaining saidhousing'm covering position above said end (1111:1118 rotation of saidshaft in moving said switch ,from closed to open position, whereby saidend is covered in every position at all times.

3. In an electric switch, the combina tion of a shaft, means for rotatinsaid shaft, an insulator carried by said she a contact member carried bysald insulator, said contact member having an end adapted to engage acompanion contact mem er, a link ivotally connected with said contactmemer, a rotector housing above theengaging end 0 said contact memberand pivotally connected thereto, and means extending from said housingto said link for maintaining said housing in position above saidengaging end of said contact member during rotation of said shaft inmoving said switc from closed to open position.

4. In an electric switch, the combination of a pair of parallel shafts,means for simultaneously rotating said shafts in opposite directions, aninsulator carried by each of said shafts, a contact member carried byeach of said insulators, said contact members having ends adapted toengage each other, a protector housing above each of said engaging endsand movable with said contact members, and means for maintaining bercarried by each of said shafts said contact members adapted to bebrought into engagement with each other when said switch 1s m closedposition, a protector housing carried by eac means for simultaneouslyrotating said shafts in opposite directions from one predeterminedposition of said shafts to another at a rate of speed graduallyincreasing from the startin point to substantially the midpoint of t epath of travel of said shafts and at a rate of speed gradually decreasinfrom substantially the mid-point to the end of said path of travel.

6. In an electric switch, the combination of a pair of parallel shafts,a contact member carried by each of said shafts, said contact membersadapted to be brought into engement with each other when said switch isin closed position, means for simultaneously rotating said shafts inopposite directions from one predetermined position of said shafts toanother at a rate of speed adually increasing from the starting point tosubstantially the mid-point of the path of a pair of parallel'shafts, acontact member carried by each of said shafts, said contact membersadapted to engage each other when said switch 1s in closed position, atoggle having a pair of arms pivotally connected with each other andforming a substantially straight line with each other when said switchis in closed position and means for moving the pivotal point ofconnection of said to gle arms, whereby said shafts will be rotate inopposite directions at a gradually increasing rate of'speed and saidcontact members will be separated from each other.

8. In an electric switch, the combination of a pair of parallel shafts,a contact member carried by each of said shafts, said contact membersadapted to engage each other when said switch is in clos position, atoggle having a pair of arms pivotally connected with each other andformin a substantially strai ht line with eac other when said switc isin closed position, a bell crank lever, a link extending from thepivotal point of connection of said toggle arms to one arm of said bellcrank lever, said arm and said link adapted to he broughtintosubstantially a straight line when the of said contact members, anda switch is in open position, and means for actuating said bell cranklever.

9. In an electric switch, the combination of a pair of parallel shafts,a contact member carried by each of said shafts, said contact membersadapted to enga e each other when said switch is in close position, atoggle having a pair of arms pivotally connected with each other andforming a substantially straight line with each other when said switchis in closed position, a bell crank lever, a link extending from thepivoted point of connection of said toggle arms to one arm of said bellcrank lever, said arm and said link adapted to be brought intosubstantially a straight line when the switch is in open position, meansfor actuating said bell crank lever, and a drag link connecting saidshafts, whereby the latter will be moved synchronously.

In witness whereof I hereunto subscribe my name this 23rd day ofNovember, A. D.

JOHN R. TOWNSEND.

Corrections in Letters Patent No. 1,275,326.

It is hereby certified that in Letters Patent No. 1,275,326, grantedAugust 13,

1918, upon the application of John R. Townsend, of Chicago, Illinois,for an improvement in Air-Break Switches, errors appear in the printedspecification requiring correction as follows: Page '4, strike out lines11 to 27 and 86 to 116,

comprising claims 1, 6, and 7; renumber claims 2, 3, 4, 5, 8, and 9 as I2, 8, 4, 5, and 6; and that the said Letters Patent should be read withthese corrections therein thatthe same mayconform to the record of thecase in the Patent Office.

Signed and sealed this 8th day of October, A. 1)., 1918.

R. F. WHITEHEAD,

Acting Commission" of Patents.

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